1. Technical Field
Embodiments of the present disclosure relate to embedded network devices, and more particularly to a firmware upgrading method of an embedded network device.
2. Description of Related Art
An embedded network device, such as an ADSL router, may require its firmware to be upgraded, which is an embedded operating system of the embedded network device. The embedded network device cannot boot up if the firmware is damaged. Upgrading the firmware requires flash memory of the embedded network device to be rewritten and firmware to be replaced with a newer version. Thus, the firmware requires to be successfully upgraded and failure is unpermitted. However, many factors, such as cutoff of the power supply to the embedded network device during the firmware upgrading can bring the failure. Therefore, the embedded network device backups the firmware to avoid the firmware damage.
Generally, the firmware is stored in a NOR flash of the embedded network device. Now, price of the NOR flash is very high. For example, a 4 MB nor flash substantially costs 0.6 USD, an 8 MB nor flash substantially costs 1.1 USD, and a 16 MB NOR flash substantially costs 2 USD. Thus, the NOR flash plays an important role in the cost of the embedded network system, especially in large manufactures. For example, the firmware of the embedded network system needs 2.1 MB, and then the backup system of the firmware also needs 2.1 MB. Then, the embedded network system requires including an 8 MB NOR flash, which double the cost. Then, it is very important to decrease the cost on the NOR flash and simultaneously assures the reliability of the firmware upgrading.